1. Field of the Invention
The present invention relates to a computer system including a host computer and storage systems. More specifically, the present invention relates to a method for data transfer and data management between storage systems.
2. Description of Related Art
Computer systems generally execute “backup” processing to preserve replica or compressed data of the original data on storage media such as magnetic disks or magnetic tapes, in case of data loss due to system failure, bugs in software, human error, etc. Backup processing in computer systems is normally executed periodically based on a backup schedule.
The “D2D2T (Disk to Disk to Tape)” system is a known backup system. In this “D2D2T” system, data used in a host computer or similar is stored on magnetic disks, the data is backed up as a primary backup on different magnetic disks, and further the backed-up data is also saved to magnetic tapes as a secondary backup. A system that realizes the above “D2D2T”-type system is typically provided with a magnetic disk device for storing the original data, a backup magnetic disk device for storing primary backup data, and a magnetic tape device for storing secondary backup data.
Japanese Patent Laid-open Publication No. 11-242570 discloses a technique to provide an external storage system with a backup magnetic disk device and a tape library device having a plurality of magnetic tapes, and to automatically save data on a magnetic disk to a magnetic tape via a controller in the external storage system.
Further, Japanese Patent Laid-open Publication No. 2002-297456 discloses a technique to form a new route using another available device if a certain device on the route between the apparatuses necessary for backup processing becomes unavailable due to a device failure or similar, and to thereby reduce the extra backup processing time necessitated by the device failure.